1. Field of the invention
This invention relates to a cylinder lock and key therefore, the lock comprising a housing, a cylinder core mounted for rotation in the housing, a slot extending into the cylinder core, parallel to the rotational axis thereof, for receiving the key, and a row of locking pins of circular cross-section guided in bores in the cylinder core, which bores intersect over parts of their length with said slot, the pins being movable against spring means when a key is inserted into the slot. The invention also relates to the key for such a combination, and a method of manufacturing the key.
2. Description of prior art
There have been many proposals hitherto for cylinder locks incorporating different modes of engagement between the locking pins and the key. For example, British patent specification No. 1543940 describes a lock in which the cylinder core has two rows of parallel pins which have pointed ends, the pins in each row engaging a respective one of two parallel coded parts on the edge of the key.
The key for such a lock, however, must be comparatively thick in order for it to be able to co-operate with the pointed ends of the locking pins. Thus, the width of each of the coded parts of the key must be at least half the thickness of the pins. This represents a disadvantage if it is desired to reduce the diameter of the cylinder core to a minimum value. A further disadvantage is that the points of the locking pins, and the coded surfaces on the key, are subject to wear, thereby shortening the useful life of the lock.
Published French patent application No. 2378929 discloses a key which has along its edges, two rows of coded recesses. However, such a key is intended for use with a lock employing flat tumblers, rather than locking pins as the present invention is concerned with.
British patent specification No. 1,557,245 discloses a cylinder lock and key combination with a flat key which has codes on its side for engagement with pins disposed at 90.degree. and 45.degree. to the general plane of the key. However, there is no provision for guiding the pins between their engagement with operative parts of the codes, and hence the pins and key are subject to considerable wear in service.
It is the object of the present invention to provide a cylinder lock and key in which the aforementioned and other disadvantages of known locks are overcome or reduced.